Inspired - appropriately enough - by this Ideas & Inspiration post:
http://beyondthesprues.com/Forum/index.php?topic=147.msg2025#msg2025Vickers Valiant K.2The Vickers 
Valiants were withdrawal from RAF service in Dec 1964 due to severe metal fatigue in the main wing spars. 
Valiant B(PR).1s were replaced by 
Victor B.2s converted to 
Victor SR.2 standard. Most critical was the retirement of the 
Valiant B(PR)K.1 tankers which left the RAF with no front-line in-flight refuelling aircraft.
One proposal was to convert surplus 
Victor B.1A bombers to B(K).1A tanker standard. But that would require the RAF to retain the Armstrong Siddeley 
Sapphire turbojet in service for this one aircraft type. The British Aircraft Corporation counter-proposal had the advantage of employing more modern turbofans already in service with the 
Victor B.2 and VC10 - the Rolls-Royce 
Conway.
The BAC proposal was accepted and, as the 
Valiant B(PR)K.1s were phased out our service, they were returned to their manufacturer for extensive rebuilds. Wings were 'plucked' of control surfaces and systems to be installed in wings of an entirely new design. The main undercarriage was also reused - albeit, heavily modified so that the gear now retracted inward.
The 
Valiant's original 'buried' powerplant approach was abandoned in favour of four separate pylons for podded engines. This arrangement produced more drag but, even in their derated form, the new 
Conway turbofans produced almost twice as much power as the original Rolls-Royce 
Avon RA28 Mk 204 turbojets. Thus rebuilt, the first 
Valiant K.2 re-entered RAF service in March 1966 - serving with 90 Squadron at RAF Honington and 214 Squadron at RAF Marham.
With their new wings (employing a stronger alloy) and freed from the strains of low-level bombing flights, the 
Valiant K.2s would prove both durable and reliable. The 
Valiant K.2 performed sterling service during the Falklands War. The sturdy Valiant K.2s were finally retired in October 1993. The 
Valiants were replaced by 757 K.1s (ex-British Airways Boeing 757-200s converted for IFR).